Thursday, October 04, 2007

Cellular energy booster

All living cells are powered by a molecule called adenosine triphosphate or ATP. It is a mobile power store that carries energy from the breakdown of nutrients in the form of double bonds within its structure. Its energy can be released when and where the cell needs it by breaking these bonds.

However, when the blood flow is stopped to a region of the body, during a heart attack, for example, the supply runs out. Researchers have tried to get around this problem by injecting ATP directly into the bloodstream. But this has had limited success, because the ATP rarely makes it to the inside of the cells. Now William Ehringer from the School of Medicine at the University of Louisville, US, plans to deliver ATP by encapsulating it within a wrapper of fatty lipid molecules.

The resulting tiny containers, or vesicles, are then injected into the bloodstream and distributed around the body. Importantly, the lipids are similar to those in the membranes of cells within the body. As a result, the vesicles will be partially absorbed into the cells, ensuring that the ATP is delivered directly where needed.

Ehringer has tested the technique with cells from human umbilical cords and says it works well. However, more tests will be needed to see whether it has a clinically valuable role to play in humans.

The method of using vesicles to carry biomolecules directly to cells within the body is not limited to ATP alone, and might have other useful applications in the future.